These mSata SSDs run on 3.3v not 5.0v.
That information is a misprint. All mSata drives accept the same voltage and that is 3.3v. Check the photo attached.
Re the iRiver, not all mSata drives will work in the iRiver H300 series. The limitation appears to be peak current use. I had a lot of difficulty, for instance, with a Mushkin 250GB mSata unit. The only way to confirm compatibility is to take a punt, buy one, and check it out - or wait for someone else to do that. Who's first?